ELECTRIC-FIELD SOUNDINGS THROUGH THUNDERSTORMS

We report on 12 balloon soundings of the electric field in thunderstorms. The maximum magnitude of E in the storms averaged 96 +/- 28 kV/m, with the largest being 146 kV/m. The maximum was usually observed between vertically adjacent regions of opposite charge. Using a one-dimensional approximation to Gauss' law, we infer four to ten charge regions in the storms. The magnitude of the density in the charge regions varied between 0.2 and 13 nC/m3. The vertical extent of the charge regions ranged from 130 to 2100 m. None of our 12 storms had charge distributions that fit the long-accepted model of Simpson and colleagues of a lower positive charge, a main negative charge, and an upper positive charge. In addition to regions similar to the Simpson model our storms had screening layers at the upper and lower cloud boundaries and extra charge regions, usually in the lower part of the cloud.